Since way before in his first life, he was naive. I mean, he lost all hope. clinging only to a single person, Irene. That's already pretty naive. Its even showed that he fight through 100 soldiers just to find Irene. Not that I can blame him with all that trauma. The only way to fix a Naivety is through old age, experiencing different things. He died like around 25, he starts again with 0, he's just repeating things, not experiencing different things. He does experience some difference, magic. And insecurity from Tina.